The 24-year-old failed to secure first-team football at Portsmouth since joining the club in a £6million deal in 2007.
“I glad to be home really,” he told Sky Sports News. “Hopefully I can make the same impact in the North as I did at Preston.
“I’m just glad to get away and hopefully get some games under my belt and start scoring some goals.
“I don’t think I was being given a fair chance. Every time I played it was as a winger. I’ve come here to play as a striker.”
“I’ve not set any targets yet,” he continued. “I’ve got to get match fit first and get a few games under by belt. Match fitness is the key thing in football.”